Rotary core drill



June 29 1926.

G. KAMMERER ET AL ROTARY CORE DRILL Filed Sept. 15 1924 Patented June 29, 1926.

UNITED. STATES PATENT OFFICE.

GEORGE KAMMERER, OF WHITTIER, AND FRANK HILL. OF LOS ANGELES, CALIFOR- NIA, ASSIGNORS TO SPENGLER CORE DRILLING COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

ROTARY CORE DRILL.

Application filed September 15, 1924. Serial No. 737,733.

This invention. relates to a rotary core drill of the type employed for drilling and testing formations and deep oil wells by the rotary method.

The rotary core drills now employed for drilling and testing formations in deep oil wells are generally of the so-called double barrel type, i. e.. the core drills comprise a barrel to receive the core formed by the drill and an outer barrel which is employed for the two-told purpose of passing flushing fluid to the cutters of the drill, the flushing fluid passing outside of the core receiving barrel, and to provide a support for certain outer cutters of the drill which outer cutters are employed to drill the hole to a larger diameter than that of the core extracted.

An object of the present invention is to provide a simplified and improved rotary core drill which 'employs but a single barrel. the core drill having the single barrel forming a core receiving chamber and including separate passages for the flushing fluid to be supplied to the drillthe single barrel also supporting both the core forming cutters of the drill and the bore enlarging cutters. The single barrel forming both the flushing passages and the core receiving chamber, while the core forming cutters are secured to the single barrel, permits the customary outer barrel to be eliminated and results in a more rigid and sturdy drill. Another object of the present invention is to provide a rotary core drill so constructed that the flushing fluid passed to the cutters is prevented from destroying the core as formed and thereby provide a rotary core drill which will positively take a true core of the formation in the well.

Various other objects and advantages of this invention will be apparent from a description of the preferred form of rotary core drill embodying the invention. For this purpose, reference is made to the accompanying drawings illustrating a preferred example of the invention.

Tn the drawings:

Figure 1 is an elevation of the rotary core drill;

Fig. 2 is an elevation in vertical section of the drill shown in Fig. 1.

Fig. 3 is a section on the line 3-3 of Fig. l.

Fig. 4 is a section on the line 4-4. Fig. .1; and

Fig. 5 is a. section on the line 5-5 of Fig. 1.

Referring to the drawings. 1 indicates a. tube forming part of the single barrel of the drill such tube 1 being threaded at its lower endinto a joint 2 forming a continuation of the single barrel of the'drill, such joint 2 being in turn threaded at its lower end to a tubular cutter 3 forming a further continuation of the single barrel. The tube 1. joint 2 and hollow cutter3 have vertical core receiving passages 4, Sand 6, respectively. registering to form a'st'raight vertical core receiving chamber for the drill. The upperend of the tube 1 is threaded into a joint 7 in turn threaded at its upper end to a drill pipe 8 bywhichthe rotary core drill may be operated from the top of the well. The joint 7 is also provided with threaded bore 9 alined with the bore 4 of the tube 1. into which is threaded a valve cage 10 carrying av valve seat 11 upon which a ball valve 19 normally rests, the ball valve 12 preferably being normally urged against the said seat by a. compression spring 13 disposed between the upper side of the ball and top of the valve cage 10. The drill is thus provided with a self-closing or check valve operative to prevent flushing fluid from the drill pipe 8 passing into the core receiving chamber, the valve being, however, operative to permit. discharge of flushing fluid out of the core receiving chamber when the core is being admitted thereto. The joint 7 is also provided with a plurality of vertically extending and circumferentially spaced apart flushing ducts 14 communicating with the interior of drill pipe 8 such flushing ducts 14 at their lower end registering with the bores of pipes 15 extending between theijoint 7 and joint 2, which pipes are preferably rigidly secured to the tube 1 by a welding process so that the pipes 15 and the tube 1 are in fact integral. The joint 2 is also provided with flushing ducts 16 registering with the bore of pipes 15 which discharge from the lower cnd of the joint 7.

The hollow cutter 3 of the drill is provided at its lower end with suitable core forming cutter such as mill teeth 17 which are dedrill. In addition thereto hollow cutter S is provided with u pliirilitg ot' rzuliul fins or plates extending down preferahl flush with the edges of the mill teeth l7 which plates or tins 1T constitute outer cutters operutive to enlarge the hole tolnuul the drill tin-l us sist in taking the c re. Such cutters in we preferably nmde of ufticiem thin the hole after the core I no reaming; for further drill "cs :1 plurality of bracing ns on the tubular cutter 3 engugiug the lower end of the joint 12 to strengthen the drill.

The rotary core drill herein described thus contains but a single barrel, the customary outer Barrel being dispensed with end. is unnecessary. due to the provision of the outer cutters upon the hollow cutter 3 in place of employing such customary outer barrel for supporting the cutters. The flushing fluid supplied to the drill is passed through the pipes 15 which are welded to the tube 1 so as'to constitute an in tegrsl part thereof and the entire rotary o for talxin all cores in deep oil wells It will no noted that the flushing passages 16 discharge at 9. point above the upper end of the cutters l8 and :1. substantial distance from the mill teeth 17 of the hollow cutter 3. The distance between the discharge point of such flushing fluids anti the inill teeth 17 is in practice preferably over eight inches and permits the flushing fluid to be dis chmed Where the pulsations of the pump forcing the fluid to the bottom of the well will not act at the. mill teeth 1? to disintegrate the core being taken by the drill. Actual tests with core drill of this invenore'drili is of rigid construction Well suited rseosm tiou discloses that the core taken is at. all times void of any disintegration clue to the action of the flushing drill.

While the form of rotary core drill herein particularly described is Well suited to accomplish the purpose of this invention, it understood that various modifications may he made without departing from the spirit of the invention. The invention is of the scope set forth in the appended claims.

We cluinr:

1. A rotary core drill comprising a core receiving barrel having a plurality of pipes welded to the barrel, core forming cutters at the lower end of the drill, core enlarg in; cutters secured to the lower end of the drill, and tr self closing valve at the upper end of said barrel.

2. A rotary core drill, which comprises a single barrel having core receiving means,- nieans forming exterior flushing passages extending downwardly along the core receiving means, a hollow cutter carrying core forming cutters and bore enlarging cutters the flushing passages discharging more than eight inches above the core or the drill.

3. A. rotary core drill comprising a core receiving barrel, a core cutting head connected with the barrel and having core cutting teeth, radial bore enlarging cutters integral therewith, and a plurality of pipes placed against the side of said core receiving barrel for conveying flushing fluid to the vicinity of said core cutting head.

Signed at Los Angeles, California, this 6th day of Sept. 1924.

GEORGE KAMMERER. -.FRANK HILL.

forming cutters fluid supplied to the 

